Flow distributor



Nov. 1, 1966 w. L. MANN ETAL FLOW DISTRIBUTOR Filed May 15, 1963 n m a T wmm v NQNN [MM R mm LB 9 m e 0 9 MW vw 00 wk L mv WH mm BY MwUJ AGENT United States Patent 3,282,248 FLOW DISTREBUTOR Warren L. Mann, Westernport, Mal, and Howard B.

Mehlman, New Creek, W. Va., assignors to West Virginia Pulp and Paper Company, New York, N.Y., a

corporation of Delaware Filed May 15, 1963, Ser. No. 280,519 6 Claims. (Cl. 118-612) This invention relates to liquid flow distributing apparatus. The apparatus finds great utility in the distribution of paper coating mixtures, adhesives, and sizing mixtures, and may be used in other areas where mixing and circulation of viscous materials is difficult to achieve.

The invention will be described with relation to its adaptability to the paper coating art, and more particularly, it will be disclosed in reference to its use in the coating pan of a paper coating machine. In a conventional coating pan, coating enters the coating pan through one or more inlets and the excess coating is carried away through an overflow pipe. There is no means for agitating the coating in the coating pan. With such equipment, dead areas occur in the coating pan where the coating material is substantially idle. As the coating material is applied to a traveling web of paper, as for example by an applicator roll, the coating material in the dead areas tends to dewater, i.e., the traveling web of paper absorbs the liquid portion of the coating mixture, leaving a substantial amount of the solids in the coating mixture in the coating pan. The dewatering of the coating material in the dead areas results in a. higher solids level in these areas. At the same time, due to the rather viscous nature and sluggish flow of paper coatings, areas of relatively lower solids level tend to occur at points where fresh coating material is admitted to the coating pan. The non-uniformity of solids content in the coating pan is transferred to the traveling web during the coating operation, resulting in nonuniformity of coat weights being applied across the web.

The apparatus of this invention admits fresh coating material uniformly into and throughout the coating pan and prevents dead areas from occurring within the coating pan. The flow distributor of this invention primarily comprises two slotted, concentric conduits with means to rotate the inner conduit in such fashion that slots in the inner and outer conduits become aligned at intervals along the length of the conduits to emit coating to the coating pan in a uniform manner. The continual, uniform distribution of coating to the coating pan prevents the "formation of dead spaces and thereby prevents the formation of localized are-as of high and low solids levels in the coating pan.

The invention will be best understood by reference to the drawings, in which: I

FIGURE 1 is a longitudinal view of the how distributor of this invention;

FIGURE 2 is a sectional View taken at AA of FIG- URE 1;

FIGURE 3 is a sectional view taken at BB of FIG- URE 1;

FIGURE 4 is a vertical sectional view of a blade coater, in which the coating pan is equipped with the novel flow distributor of this invention;

FIGURE 5 is a longitudinal sectional view of the coating pan of FIGURE 4.

From FIGURES 13, it is seen that inner conduit or pipe 18 is housed within outer conduit or pipe 12. Conduit 18 contains a series of slots or openings 14 which are evenly spaced in helical fashion along the length of conduit 10. Inner conduit is open at end 16 and is closed at end 18. Shaft 20, attached to inner conduit ice 10 at end 18, carries a pulley 22 driven 'by motor 24 by means of pulley 26 and pulley belt 28. Any suitable drive means may be employed to rotate inner conduit 10.

Outer conduit 12 contains a series of slots or openings 30 evenly spaced along the length of conduit 12 in a straight line parallel to the longitudinal axis of conduit 12. Slots 38 in outer conduit 12 are spaced apart at a distance equal to the spacing of slots 14 along the longitudinal axis of inner conduit 18. A suitable seal is provided at 11 to prevent leakage.

Coating material, or other liquid as the case may be, is supplied to conduit 12 by any suitable means, such as a. supply pipe from a source of coating material, and the coating material is introduced into conduit 12 at opening or inlet 32 and the coating material flows into conduit 18. As conduit 10 is rotated in the direction of the arrow by means of the driving apparatus disclosed above, one slot .14 at a time in conduit 10 becomes aligned with a corresponding slot 30 in conduit 12, as shown in FIGURE 2. Because of the helical placement of the slots in conduit 10, flow of coating material from the slots 30 of conduit 12 takes place from left to right (as shown) along the length of conduit 12 as each slot 14 in conduit 10 becomes aligned with a slot 30 in conduit 12 to provide a flow path for the coating material. FIGURE 3 illustrates the disal-ignment of a slot 14 in conduit 10 with a slot 30 in conduit 12 with the result that no flow takes place from that particular slot 30 at that particular time.

As shown in FIGURES 4-5, the flow distributor disclosed above may be employed in combination with the coating pan of a paper coating apparatus, as for example, a blade coater. The blade coater comprises a backing roll 40, an applicator roll 42, and blade 44. Applicator roll 42 transfers coating material from the coating pan 46 to the traveling web P, and the coating material applied to the web P is metered and smoothed by blade 44.

Coating pan 46 is preferably comprised of an elongated semi-cylindrical bottom 48 and end walls 50 and 5-2, but the bottom of the pan may be flat instead of semi-cylindrical, in which case side walls and end walls are attached to the bottom to form the coating pan. Outer conduit 12 of the flow distributor extends longitudinally of the coating pan 46, butts against end wall 50, and extends through and slightly beyond end wall 52. The joint between end wall 52 and conduit 12 is sealed to prevent leakage from the coating pan by means of seal 54 which is held in place by plate 56, the latter being tastened to end wall 52 by screws 58 and nuts 60. Inner conduit 1t) likewise extends through and beyond end wall 50, and the joint between end wall 50 and conduit 10 is suitably sealed to prevent leakage but allowing rotation of conduit 18. In this instance, the seal is effected by means of a coupling 62 comprised of female member 64, which houses a sealing compound 66, and a male member 68. Screws 70 pass through the flange 72 of member 68, into and through member 64, through end wall 50, and are secured by nuts 74. The sealing compound 66 prevents coating material from leaking from the coating pan 46.

The bottom 48 of the coating pan 46 may have a. recessed channel 76 which extends longitudinally of the bottom 48 of the coating pan 46, but, of course, the channel is not essential. The channel 76 serves as a means to place the flow distributor in the lower-most part of the coating pan 46.. With or without the channel 76, outer conduit 12 is so disposed within the coating pan 46 that slots or openings 30 are normally directed up wardly toward applicator roll 42, but conduit 12 may be rotated as desired to change the direction of the flow paths for the coating material into the coating pan 46.

As conduit 10 is rotated by suitable driving means, as disclosed above, coating material, being supplied at inlet 32 of conduit 12 by supply line 33 which is connected to conduit 12 by nipple 31, is uniformly admitted to and distributed throughout the coating pan 46 as each of the slots 14 in conduit become aligned with a corresponding slot 30 in conduit 12. Because of the uniform admission of coating material to coating pan 46 and its uniform distribution throughout the coating pan 46, the formation of dead spaces within the coating pan is prevented, and the coating material transmitted to the traveling web is of uniform solids content, resulting in a paper product which is coated with a uniform coat weight across the web.

In the preferred embodiment of the invention, outer conduit 12 is made of a self-lubricating material, such as polyvinyl chloride, and inner conduit 10 is made of stainless steel. The outer diameter of the inner conduit 10 is slightly smaller than the inner diameter of the outer conduit 12 in the range of about .010 to .050 of an inch to facilitate the rotation of inner conduit 10 with respect to outer conduit 12. The self-lubricating nature of outer conduit 12 also facilitates rotation of inner conduit 10.

From the above disclosure, it is apparent that coating material could be supplied to the inner conduit, rather than to the outer conduit, and the outer conduit could be rotated with respect to the inner conduit, and the same results would be achieved in the distribution of the coating. It is also apparent that the flow distributor of this invention is not limited in use to any particular type of coating apparatus or coating material, but is adaptable for use wherever uniform distribution of a liquid material is essential.

The above disclosed flow distributor, used in combination with the coating pan of an on-the-machine paper coating apparatus, has found great utility on commercial paper machines. Its use has resulted in the production of a more uniformly coated commercial paper product.

While certain embodiments of the invention have been illustrated and described, it is to be understood that various changes may be made therein and the invention embodied in other structures, and it is not intended to limit the patent to the specific constructions illustrated.

We claim:

1. In a coating apparatus for applying a liquid coating material to a traveling web of paper and the like, in combination, a coating pan having a bottom, side walls and end Walls, a first conduit extending longitudinally within said coating pan, said first conduit having openings spaced along its length, second conduit having openings spaced along its length, said second recited openings being helically arranged about said second conduit and spaced along the axial extent thereof so as to corerspond with said first recited openings, said second conduit being housed within said first conduit, means connecting with one of said conduits for continuously supplying a liquid coating material to said conduits, and driving means connecting with one of said conduits for continuously rotating said one conduit with respect to the other conduit whereby to communicate, one at a time, the openings of said second conduit with the corresponding openings of said first conduit and to provide flow paths for the liquid coating material into said coating pan.

2. In a coating apparatus for applying liquid coating material to a traveling web of paper and the like, in combination, a coating pan comprising an elongated semicylindrical bottom and first and second end walls attached to said bottom, a first conduit extending longitudinally within said coating pan and through the first end wall, said first conduit having a plurality of openings spaced at intervals in a straight line along that portion of its length confined within said coating pan, a second conduit housed within said first conduit and extending through the second end wall of said coating pan, said second conduit having a plurality of openings helically arranged at intervals along that portion of its length confined within said coating pan and spaced apart with respect to the longitudinal axis of said second conduit at distances equal to the spacings of openings along the length of said first conduit, means connecting with said portion of said first conduit extending through said first end wall of the coating pan for continuously supplying a liquid coating material to said conduit, and driving means connecting with said portion of said second conduit extending through said second end wall of the coating pan for continuously rotating said second conduit with respect to said first conduit whereby each opening in said second conduit becomes aligned, one at a time, with a corresponding opening in said first conduit as said second conduit rotates continuously within said first conduit, to provide flow paths for the liquid coating material from said conduits into the coating pan.

3. The flow distributor of claim 1 in which said first conduit is comprised of a self-lubricating material.

4. The flow distributor of claim 1 in which said first conduit is comprised of polyvinyl chloride.

5. The apparatus of claim 2 in which said first conduit is comprised of a self-lubricating material.

6. The apparatus of claim 2 in which said first conduit is comprised of polyvinyl chloride.

References Cited by the Examiner UNITED STATES PATENTS 944,026 12/ 1909 Fowden 137-6253 X 1,749,182 3/1930 Fox 118-429 X 1,861,142 5/1932 Scherrer. 2,143,565 1/1939 Minea 137--625.32 2,168,997 8/1939 Lankes et al 118429 X 2,387,736 10/1945 Bierman 118-429 X 2,533,167 12/1950 Kilham 117429 X 2,658,471 11/1953 Bledsoe 1l8429 X 3,119,363 1/1964 Rieben.

FOREIGN PATENTS 866,092 3/ 1941 France. 447,219 5/1936 Great Britain.

MORRIS KAPLAN, Primary Examiner. 

1. IN A COATING APPARATUS FOR APPLYING A LIQUID COATING MATERIAL TO TRAVELING WEB OF PAPER AND THE LIKE, IN COMBINATION, A COATING PAN HAVING A BOTTOM, SIDE WALLS AND END WALLS, A FIRST CONDUIT EXTENDING LONGITUDINALLY WITHIN SAID COATING PAN, SAID FIRST CONDUIT HAVING OPENINGS SPACED ALONG ITS LENGTH, SECOND CONDUIT HAVING OPENINGS SPACED ALONG ITS LENGTH, SAID SECOND RECITED OPENINGS BEING HELICALLY ARRANGED ABOUT SAID SECOND CONDUIT AND SPACED ALONG THE AXIAL EXTENT THEREOF SO AS TO CORRESPOND WITH SAID FIRST RECITED OPENINGS, SAID SECOND CONDUIT BEING HOUSED WITHIN SAID FIRST CONDUIT, MEANS CONNECTING WITH ONE OF SAID CONDUITS FOR CONTINUOUSLY SUPPLYING A LIQUID COATING MATERIAL OF SAID CONDUITS, AND DRIVING MEANS CONNECTING WITH ONE OF SAID CONDUITS FOR CONTINUOUSLY ROTATING SAID ONE CONDUIT WITH RESPECT TO THE OTHER CONDUIT WHEREBY TO COMMUNICATE, ONE AT A TIME, THE OPENINGS OF SAID SECOND CONDUIT WITH THE CORRESPONDING OPENINGS OF SAID FIRST CONDUIT AND TO PROVIDE FLOW PATHS FOR THE LIQUID COATING MATERIAL INTO SAID COATING PAN. 